Index: lib/Sema/SemaCast.cpp
===================================================================
--- lib/Sema/SemaCast.cpp
+++ lib/Sema/SemaCast.cpp
@@ -1078,7 +1078,9 @@
               return TC_Failed;
             }
           }
-          Kind = CK_BitCast;
+          unsigned SrcAS = SrcPointee.getAddressSpace();
+          unsigned DestAS = DestPointee.getAddressSpace();
+          Kind = SrcAS != DestAS ? CK_AddressSpaceConversion : CK_BitCast;
           return TC_Success;
         }
 
Index: test/CodeGenCXX/address-space-cast.cpp
===================================================================
--- /dev/null
+++ test/CodeGenCXX/address-space-cast.cpp
@@ -0,0 +1,8 @@
+// RUN: %clang_cc1 -emit-llvm -o - %s
+
+typedef void *void_ptr;
+typedef int __attribute__((address_space(1))) *int_ptr_1;
+
+void test_cstyle_cast_from_void_ptr(void_ptr vp) {
+  (void)(int_ptr_1)(vp);
+}